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Problems and Countermeasures of Air Conditioning Systems in Internet Data Centers in Xi’an city Xiaohong Yanga, Zhiwei Wangb, and Xiang Jingc Xi’an University of Architecture & Technology, Xi’an, Shaanxi, 710055, P.R.China a776995609@qq.com, bWzhiwei-atu@163.com, c410419290@qq.com Keywords: air distribution, high temperature alarm, system energy efficiency, internet data center, countermeasures Abstract.
Site investigation on air conditioning systems (ACS) in three internet data centers (IDCs) in Xi’an city was conducted, the relative data used for issues analysis was obtained from on-site testing of temperature field and velocity field in IDCs and online working meter on power distribution box of ACS and computer cracks, the field investigation found that there were three main problems: high temperature alarm of larger power electronic components in computer cracks; irrational air distribution around computer cracks; and not high energy efficiency of ACS.
They include the cold and hot air stream mixing, nonuniform of static pressure in underfloor plenum chamber, and air temperature rise of jet flow in upper air supply mode etc., and lead to the energy efficiency reduction of ACS.  
The improvement measures of system efficiency will be taken in three aspects: 1) a rational air distribution should be designed according to different demand of microthermal environment of CRs in IDCs; which involves air supply pattern selection and individuation demand satisfaction etc.; 2) for air cooling type of condenser with water spray, based on testing data from field or manufacturer, the optimal time of water spray and interval of twice spray can be determined for best heat exchange effectiveness; 3) by adding an independent fresh air system, outdoor air natural cooling resource can be fully used in transitional seasons and winter, thus electricity power consumption of refrigerator will greatly decreased during corresponding period; 4) by using water loop heat pump system, a great deal of heat from CRs in IDCs can be absorbed and transferred into a zone of heating demand or as a heat source for hot water supply in IDC building.
C&AC.21 (2007), p. 105-107 [4] Xiang Jing: Test and research on the Air-conditioning system in Internet Data Centers.

This strain exhibited strong reduction activity against Cr6+.
However, there are few data concerning this organism’s resistance to chromium.
Reduction reaction of D. radiodurans on Cr6+.
Data processing and analysis.
However, the chromium reduction activity of resting cells is very low.

First, five controlling factors of load were defined, which were single reduction amount (δ), reduction rate (ν), thickness of top die (ω), rotary angle (θ) and rotary way (γ) respectively, and their influence degree on load was studied later.
An appropriate material model was built to simulate, which was based on the flow stress-strain data of SA508 Class 3 steel in different temperatures and strain rates.
Before the next reduction top die should rotate an angle of 90°-θ at an anticlockwise direction.
As to this heavy and thick-walled container head, the overall forging process could be divided into three coherent stages considering the former investigation data, and the best combination mode of the values of five controlling factors was found by simulation experiments.
However, stepwise rotary way was used to raise production efficiency in stage 2 and stage 3, and smaller single reduction amount and reduction rate was accepted to reduce load.

Moreover, the reduction annealing could affect the appearance or diminishing WFM.
The 2D Fourier difference map of the neutron diffraction data at lattice plane [0 0 0.49c] are shown in Fig. 2.
It is found that the neutron scattering density between the observed and the calculated data at around the Cu-site increases (~4.65%) through the annealing process.
Normally, the aim of the reduction annealing process is to create oxygen vacancy in the sample.
Koike, Ce-Doping and Reduction Annealing Effects on Magnetic Properties of Pr2-xCexCuO4 Nanoparticles, J.

Referring to the source of the research, the data are taken from two variable groups: latent variable and indicator variable.
The data collection techniques are field observation method, laboratory observation, interview, and scale method.
Results and Discussion In order to generate representative study result, two activities are exercised; data collection and measurement, and theoretical structural model development as a prototype model.
Data collection and measurement are to be the first step to generate more representative data for indicators in every latent variable.
The activity is firstly started by collecting dust from particular area or environment and compiling housing data.

On the other hand, the reduction in strength and weight loss of specimens increased with increase in the exposure time.
Limited experimental data reported by Torii and Kawamura [8], found that FA and silica fume appear to increase the resistance significantly, but only when the amount is above a certain level, which is dependent on the type of sulfate solution.
However, limited data is available on the effects of RHA as a replacement of Portland cement subjected to sodium sulfate solution via wetting and drying cycles.
Data from Table 1 shows that the main component of RHA is SiO2.
The reduction in compressive strength of specimens increased at the earlier age of exposure.

Through this study, it is thought that the slip dissolution/oxidation dominantly contributes to the reduction in the fatigue life at a strain rate of 0.008 %/s and the HIC is mainly responsible for the reduction in the fatigue life at strain rates of 0.04 and 0.4 %/s.
Fig. 1 shows the fatigue life data of SA508 Gr.1a LAS with various strain rates in air, and in 310 o C deoxygenated water [6].
Moreover, as strain rate decreased from 0.4 to 0.008 %/s, the reduction in the fatigue life in 310 o C deoxygenated water was slightly enhanced.
From microstructure observation, we found evidences of the EAC mechanisms related to the reduction in the fatigue life in 310 o C deoxygenated water were on the fatigue surface and sectioned area.
From the analysis of microstructure, it is thought that the slip dissolution/oxidation dominantly contributes to the reduction in the fatigue life at a strain rate of 0.008 %/s and the HIC is mainly responsible for the reduction in the fatigue life at strain rates of 0.04 and 0.4 %/s.

It is connected to a custom PC, that has the capability for both spindle motion control and carriage vertical applied load control, and data acquisition and display unit (monitor).
Experimental design and data collection.
Data is displayed in real time on the monitor.
The analysis is done to extract all the information present in the data, taking account of variability and measurement error.
The analysis of variance (ANOVA) is done on the experimental data to evaluate the statistical significance of the model.

Primary sources of data will include among others Google Scholar, Scopus, Web of Science, Science Direct and ASCE Library.
Examples of research data from FEMA and other seismic local institutes in the area of study will also be incorporated into the study.
Technical papers and scholarly periodicals will be the sources of data.
Evaluating these approaches' efficacy, viability, and suitability in diverse seismic contexts is the aim. 4 Experimental Data Review The goal of this project is to gather and assess experimental data on liquefaction-minimizing techniques.
Surveys and published articles on the behavior of soil before and after earthquakes are among the data sources.

In addition, a data acquisition system is used to collect experimental parameters, record data in real time, and perform data consolidation.
Through the use of a Data Acquisition (DAQ) card, load data can be transmitted to each sensing component.
Instead, the data for each axis and the power source for the hydraulic motor are entered separately based on the design of the external and internal axes.
In addition, the torque value detected by torque transducers between each axis can be sent back to the computer through the DAQ to aid in data recording.
When a load is applied, motor stall often occurs, and limited data are available.